Research On Low Coupling Six-dimensional Force/Torque Sensor Based On Fiber Bragg Grating

As human society enters a new era of information technology,the need for sensing and utilizing the external environment is increasing,and mechanical sensors have been attracting attention as an important tool and means for human perception of the external environment.Since the 1970 s,six-dimensional force/torque sensors have been rapidly developed in different fields due to their ability to measure comprehensive force/torque information.However,interdimensional coupling is unavoidable due to factors such as the structure of the design and machining errors,which is a key issue limiting the accuracy of the sensor.In this thesis,a lowcoupling six-dimensional force/ torque sensor based on fiber Bragg grating as a sensor member is designed with elastic special structure and measurement method,and its static and dynamic and temperature characteristics are simulated and experimentally investigated,mainly as follows:Firstly,a double-layer cross beam structure is designed for the inter-dimensional coupling problem of the six-dimensional force/torque sensor,which incorporates a spherical sliding structure based on the traditional cross-beam structure to achieve separate measurement of force and torque by the idea of sliding,and 14 FBGs are arranged on the elastic structure to achieve strain measurement of force/torque.The measurement principle as well as the sensing method are also analyzed.Secondly,the structure of the designed six-dimensional force/torque sensor is optimized,and the static and dynamic performance and temperature performance of the sensor are analyzed by finite element simulation to verify the decoupling capability of the sensor structure as well as to analyze the vibration mode and dynamic measurement performance of the structure.Finally,the static measurement platform,dynamic measurement platform and temperature test platform were built for the sensor structure,and the 3D printing method was used to create a model of the sensor structure to verify its structural performance,to verify the static and dynamic performance and temperature performance of the sensor and the applicability of the test system,to obtain the sensitivity,linearity,repeatability error and inter-dimensional coupling of each dimension of the sensor,and to analyze the sources of measurement errors,including the temperature fluctuation error of the sensor over a long period of time and the creep error of the structure under stress over a long period of time,were analyzed.Compared with the existing six-dimensional force/ torque sensors,the designed sensor in this thesis adopts a spherical sliding structure,which reduces the coupling between various dimensions and simplifies the calibration and maintenance of the sensor.And the structure is designed with overload protection device and has certain dynamic measurement capability.The sensor can be widely used for six-dimensional force/torque measurement,which is important for robotics,medical and aerospace applications.